JPH0323029A - Preform to be worked for forged spline - Google Patents

Abstract

PURPOSE:To prevent a forging flaw from being generated by forming a spline generating part from a part having different axial diameters and continuing the stepped part between both axial diameters with an inclined surface. CONSTITUTION:The preform 11 to be worked for forging the spline provides a spline generating part 11c longer than a crest diameter D2 of a spline part 21c to be generated on the axial part 11b. Accordingly, an axial diameter of a part shorter than the crest diameter D2 of the spline part 21c of the spline generating part 11c provided on the axial part 11b is set between a spline pitch diameter and a spline root diameter. An axial diameter of a part longer than the crest diameter D2 of the spline part 21c of the spline generating part 11c is set between a spline pitch diameter and the spline crest diameter D2. Further, the stepped part between both different axial diameters is continued by an inclined surface 11e. In this way, the productivity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a workpiece material for a forged spline in which a spline is cold forged onto a shaft portion.

[Prior art and problems to be solved by the invention] As is well known, hot forging and cold forging have a good yield rate and are not only superior in strength but also have good heritage properties. It is widely used as a means of producing vehicle parts.

By the way, when forging a spline to the shaft, for example, as shown in Japanese Utility Model Publication No. 53-24986, the spline portion of the shaft is formed to have a desired diameter and length. It is necessary to make a preliminary preparation.

FIG. 4 (a) shows the outer shape of the pre-shaped workpiece W.

The shaft diameter d of the spline generating portion 1a of the shaft portion 1 formed on the workpiece material W is determined by taking into consideration the flow of the material during forging, etc.
It is set to have a predetermined spline diameter D.

According to experiments, the shaft length L of the spline 3a formed on the shaft portion 3 of the spline shaft 2 completed by forging is as shown in FIG.
a>, the spline diameter is shorter than D (L<D
), it is possible to create a relatively accurate spline, but as shown in FIG. 5(b), if the axial length L of the spline 3a is longer than the spline mountain diameter D (L>D
), the contact pressure with the die during forging increases, and galling occurs between the spline 3a and the die during ejection, which not only causes forging defects, but also increases the load on the die, causing the die to deteriorate. Life expectancy will be shortened.

Therefore, when forging a spline 3a that is longer than the spline diameter D, the work must be proceeded with caution, resulting in a problem of reduced production efficiency.

[Object of the Invention] The present invention was made in view of the above circumstances, and even when the spline shaft length is longer than the spline mountain diameter, it can be easily taken out without causing warping, and the forging defects can be effectively eliminated. It is an object of the present invention to provide a workpiece material for Wi-made splines, which can prevent this, reduce the burden on the mold, extend the life of the mold, and significantly improve productivity.

[Means and effects for solving the problem] A workpiece material for a forged spline according to the present invention has a spline creation portion in the shaft portion that is longer than the mountain diameter of the spline portion to be created. The shaft diameter of a portion of the spline generating portion provided in the shaft portion that is shorter than the mountain diameter of the spline portion is set between the spline pitch diameter and the spline root diameter, and the spline portion of the spline forming portion of the spline flj forming portion is One sleeve diameter of the part longer than the thread diameter is set between the spline pitch diameter and the spline thread diameter, and the step part of the above spline creation part with different shaft diameters is continuous on an inclined surface, which is easy to use during forging. The surface pressure between the part of the spline generating portion that is longer than the spline shaft diameter and the mold is reduced, thereby preventing the occurrence of galling or the like.

[Embodiments of the invention] Embodiments of the present invention will be described below based on the drawings.

1 to 3 show an embodiment of the present invention, and FIG.
) is a side view of the workpiece material for forged spline, Figure 1 (b
) is a vertical cross-sectional view of the spline shaft, and Fig. 2 (a) is a longitudinal cross-sectional view of the spline shaft, and Fig. 2 (a) is a longitudinal cross-sectional view of the spline shaft.
Enlarged view of section IIa in a), Fig. 2(b) (Yo Fig. 1(b)
FIG. 3 is an enlarged view of the mb part, and FIG. 3 is a sectional view of the main part of the forging device.

(Structure) The sign 11 in the figure is a workpiece material for an H-shaped spline, and consists of a head portion 11a and a @ portion 1lb, and a spline generating portion 11c is formed at the tip of this shaft portion 1lb.

Further, reference numeral 21 is a spline shaft obtained by upsetting the above-mentioned forged spline workpiece material, with a head 21a and a shaft portion 2.
1b, and a spline portion 21c is created at the tip of this shaft portion 2lb.

Furthermore, the end face of this shaft portion 21b and the head portion 21a are
A center hole 21d is press-formed in the center.

The spline portion 21c of the spline shaft 21 has a length L1.
<L>D2), which has dimensions of a spline root diameter D1, a spline mountain diameter D2, and a pitch circle diameter Dp, and the length L is longer than the spline mountain diameter D2.

FIG. 2(a) shows the workpiece material 11 for the forged spline.
shows the size of the spline Ω1 component 11C.

The length lO of this spline generating portion 11c is equal to the length of the spline portion 21c of the spline shaft 21 (L−
j! 0). Moreover, the shaft diameter d2 of the spline fil+ forming part 11c from the base side to the length l1 which is equal to the spline mountain diameter D2 of the spline part 21C is the same as the spline mountain diameter D2 of the spline part 21C and the pitch circle diameter Dp. is set to a value between (Q2 > 62 > DD)
.

Furthermore, the shaft diameter d1 of the portion 12 longer than the above 11 from the base side of the spline generating portion 11G is the pitch circle diameter D.
It is set to a value between p and the spline valley diameter D1 (DI < di < DI).

Further, the step portion between the shaft diameters d1 and d2 of the spline generating portion 11c is continuously formed with an inclined surface 11d having an inclination angle θ (where θ is 45°) and a width t. This inclined portion 11d becomes a chamfered portion 21e with a width t'(t' = 42>) formed at the tip of the splined portion 21c of the spline shaft 21.

Reference numeral 31 in FIG. 3 is a forging device for upsetting the forged spline workpiece material 11 to form the spline shaft 21, in which a reinforcing ring 34 is mounted on a bolster 32 via a pressure receiving plate 33. A lower die 36 is attached to this reinforcing ring 34 via a die pressure receiving plate 35. Furthermore, a counter punch 38 connected to the ejector bin 37 faces the center of the bottom of the lower die 36, and this counter punch 38 forms a center hole 21d in the end face of the spline @21.

Further, above the lower die 36, the spline shaft 21
An upper die 39 for upsetting and shaping the head 21a of is provided oppositely,
A center punch 40 faces the center of the upper die 39. This center punch 40 forms a center hole 21d in the center of the head 21H of the spline shaft 21.

Furthermore, the upper die 39 includes a reinforcing ring 41 and a pressure receiving plate 42.
It is vertically installed on the die holder 43 via, for example.

(for production) Next, the operation of the embodiment with the above configuration will be explained.

First, the preformed In spline workpiece material 11 is set in the lower die 36 of the forging device 31 with the die holder 43 lifted up to a predetermined value, and then the die holder 43 is lowered by a lifting device (not shown).

Then, the upper die 39 vertically disposed on the die holder 43 presses the head 11a of the workpiece material 11, causing the workpiece material 11 to flow along the shapes of the die 36.39 and punch 38.40, The head 21a of the spline wheel 21 is upholstered, and the shaft portion 2l of the spline shaft 21 is
A spline portion 21c is created in b, and the head 21 is
A center hole 21d is formed in the end faces of the shaft portion a and the shaft portion 21b.

By the way, in the upsetting process of the forging device 31, the spline generating portion 11c of the workpiece material 11 and the lower die 3
The surface pressure applied between this subline generating portion 11c and
The shaft diameter (d
2) is set to a value between the pitch circle diameter Dp of the created spline portion 21c and the spline mountain diameter D2, so that uniform pressure is applied to the entire spline portion 21c. Furthermore, due to moderate friction between the spline 9I and the lower die 36, a highly accurate spline is created in the spline 9I or portion 11c.

On the other hand, the shaft diameter (d1) of the length D2 of the spline generating portion 11C is the pitch circle diameter Dp and the spline root diameter D.
1, the surface pressure generated between the length j1 and the lower die 36 during upsetting is smaller than that at the length j1. Therefore, due to the pressure difference, the material of the length 91 flows in the length 12 of the spline shaft 11G, and as shown in FIG. A chamfered portion 21e having a width t- (t-=Jl2) is formed.

As a result, the surface pressure between the length 12 portion of the spline generating portion 11G of the workpiece material 11 and the lower die 36 during forging is reduced, and galling against the lower die 36 during ejector is prevented. . Further, since galling can be prevented, the load on the lower die 36 is reduced, and the mold life is extended.

Note that the forging may be either cold forging or hot forging.

I. Effects of the Invention] As described above, according to the present invention, in a workpiece material for a forged spline, which has a spline generating portion in the shaft portion that is longer than the mountain diameter of the spline portion to be created, the spline provided in the shaft portion The shaft diameter of a portion of the wound portion that is shorter than the mountain diameter of the spline portion is set between the spline pitch diameter and the spline root diameter, and the portion of the spline wound portion that is longer than the mountain diameter of the spline portion. The shaft diameter of the spline is set between the spline pitch diameter and the spline mountain diameter, and the stepped portions of the two different shaft diameters of the spline 01 part are continuous on an inclined surface, and the spline shaft length is longer than the spline mountain diameter. Even if it is long, it can be easily taken out without galling, effectively preventing forging defects, reducing the burden on the mold, and extending the life of the mold.
Excellent effects such as greatly improving productivity can be achieved.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, and FIG.
> is a side view of the workpiece material for forged spline, Figure 1 (b
) is a vertical cross-sectional view of the spline shaft, and Fig. 2 (a) is a longitudinal cross-sectional view of the spline shaft, and Fig. 2 (a) is a longitudinal cross-sectional view of the spline shaft.
Fig. 2(b) is an enlarged view of part IIa of Fig. 1(b), Fig. 3 is a sectional view of the main part of the forging device, Fig. 4 and the following show conventional examples, Figure 4 (a) is a side view of the workpiece material for forged spline, Figure 4 (b) is a longitudinal cross-sectional view of the spline shaft, and Figure 5 is an enlarged view of the V section of Figure 4 (b) for each setting state. Fig. 11... Workpiece material for forged spline, 11c...
Spline creation part, 1lb...Shaft part, 11e...Slanted surface, 21c...Spline part, D1...Spline valley diameter, D2...Top diameter, Dp...Spline pitch, d1, d2 ...Shaft diameter. Figure 3 Figure 1 Figure 2 10 scolding, #mD2 Figure 4 Figure 5

Claims (1)

[Claims] In a workpiece material for a forged spline, the shaft portion has a spline generating portion that is longer than the mountain diameter of the spline portion to be created, wherein the spline generating portion provided on the shaft portion is longer than the mountain diameter of the spline portion. The shaft diameter of the short portion is set between the spline pitch diameter and the spline root diameter, and the shaft diameter of the portion of the spline generating portion that is longer than the mountain diameter of the spline portion is set between the spline pitch diameter and the spline root diameter. A workpiece material for a forged spline, characterized in that the stepped portions of the spline generating portion having different shaft diameters are continuous on an inclined surface.